Electronic device that receives power from power supply apparatus and method thereof

ABSTRACT

An electronic device comprises: a connector that comprises a first terminal for receiving power from a power supply apparatus, a second terminal, a third terminal, and a fourth terminal; a control unit that controls power received from the power supply apparatus via the first terminal; and a determination unit that determines a power supply capability of the power supply apparatus by using the second terminal or the third terminal and the fourth terminal, wherein the determination unit determines the power supply capability of the power supply apparatus by using the third terminal and the fourth terminal before a predetermined transition occurs in the second terminal.

BACKGROUND Field of the Invention

Aspects of the disclosure generally relate to an electronic device that receives power from a power supply apparatus and a method thereof.

Description of the Related Art

According to USB (Universal Serial Bus) standard (USB 3.0 standard, USB 2.0 standard, USB BC (Battery Charging) 1.2 standard, or the like) defined before USB Type-C standard, the power supply capability of a power supply apparatus is detectable by using D+ and D− terminals. In this specification, USB standard (USB 3.0 standard, USB 2.0 standard, USB BC (Battery Charging) 1.2 standard, or the like) which was defined before the USB Type-C standard will be referred to as a “legacy standard”. In a legacy standard, the power supply capability of a power supply apparatus is determined by using D+ and D− terminals. In the USB Type-C standard, the power supply capability of a power supply apparatus is determined by using a CC (Configuration Channel) terminal. According to the USB Type-C standard, a CC voltage (a voltage applied to the CC terminal) indicates which of the three different power supply capabilities (Default USB, 7.5 W (1.5 A, 5 V), and 15 W (3 A, 5V)) is being employed as the power supply capability of the power supply apparatus. Default USB is a power supply capability defined by a legacy standard. 7.5 W (1.5 A, 5 V) and 15 W (3 A, 5V) are power supply capabilities defined by the USB Type-C standard. Hence, a power receiving apparatus can detect the power supply capability of a power supply apparatus by the detected CC voltage. If the power supply capability of the power supply apparatus shifts from 15 W (3 A, 5V) or 7.5 W (1.5 A, 5 V) to Default USB, the power receiving apparatus is required to operate as a power receiving apparatus conforming to a legacy standard during a predetermined time defined by the USB Type-C standard.

Japanese Patent Laid-Open No. 2003-280771 discloses a method of controlling the operation of an electronic device in accordance with the power supply capability of a power supply apparatus. In Japanese Patent Laid-Open No. 2003-280771, switching of input power supply is performed so as not to exceed the power supply capability of the power supply apparatus.

A certain amount of time is required for the determination of the power supply capability of a power supply apparatus which is performed in accordance with a legacy standard. Hence, there is a possibility that the power supply from the power supply apparatus to the power receiving apparatus will be suppressed before the completion of the determination of the power supply capability of a power supply apparatus which is performed in accordance with a legacy standard. If power supplied from the power supply apparatus to the power receiving apparatus falls below the power consumption of the power receiving apparatus, the power receiving apparatus may unexpectedly stop its operation.

SUMMARY

According to an aspect of the embodiments, one or more of the problems described above that occur in an electronic device that operates as a power receiving apparatus can be solved.

According to an aspect of the embodiments, there is provided an electronic device comprising: a connector that comprises a first terminal for receiving power from a power supply apparatus, a second terminal, a third terminal, and a fourth terminal; a control unit that controls power received from the power supply apparatus via the first terminal; and a determination unit that determines a power supply capability of the power supply apparatus by using the second terminal or the third terminal and the fourth terminal, wherein the determination unit determines the power supply capability of the power supply apparatus by using the third terminal and the fourth terminal before a predetermined transition occurs in the second terminal.

According to an aspect of the embodiments, there is provided a method comprising: starting to receive power from a power supply apparatus via a first terminal for receiving power from the power supply apparatus; determining a power supply capability of the power supply apparatus by using a second terminal; and determining, before a predetermined transition occurs in the second terminal, the power supply capability of the power supply apparatus by using a third terminal and a fourth terminal.

According to an aspect of the embodiments, there is provided a non-transitory storage medium that stores a program causing a computer to execute a method, the method comprising: starting to receive power from a power supply apparatus via a first terminal for receiving power from the power supply apparatus; determining a power supply capability of the power supply apparatus by using a second terminal; and determining, before a predetermined transition occurs in the second terminal, the power supply capability of the power supply apparatus by using a third terminal and a fourth terminal.

Further aspects of the embodiments will become apparent from the following embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram for illustrating an example of components of a power receiving apparatus 100 according to the first embodiment;

FIGS. 2A and 2B are flowcharts for illustrating an example of the operation of the power receiving apparatus 100;

FIG. 3 is a timing chart for illustrating an example of the operation of the power receiving apparatus 100;

FIG. 4 is a table for illustrating the relationship between a CC voltage and power supply capabilities of a power supply apparatus 200; and

FIG. 5 is a view for illustrating the pin assignment of a connecting unit 101.

DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments, features, and aspects of the disclosure will be described below with reference to the drawings. However, aspects of the disclosure are not limited to the following embodiments.

First Embodiment

FIG. 1 is a block diagram for illustrating an example of components of a power receiving apparatus 100 according to the first embodiment.

The power receiving apparatus 100 is an electronic device that receives power supplied from a power supply apparatus 200 to which it is connected via a USB Type-C cable. Although a case in which the power supply apparatus 200 is an AC adapter (or an AC-USB adapter) that converts AC power into DC power will be exemplified in the first embodiment, the power supply apparatus 200 is not limited to the AC adapter. For example, the power supply apparatus 200 may be a portable battery or the like. Also, although a case in which the power receiving apparatus 100 is an electronic device that operates as an image capturing apparatus (e.g., a digital camera) will be exemplified in the first embodiment, the power receiving apparatus 100 is not limited to the image capturing apparatus.

As shown in FIG. 1, the power receiving apparatus 100 includes a connecting unit 101, a power source 102, a power receiving and supplying unit 103, a power control unit 104, a resistor 105, a power supply capability determination unit 106, a voltage detection unit 107, a BC device determination unit 108, and a system control unit 109. However, components of the power receiving apparatus 100 are not limited to those shown in FIG. 1.

The connecting unit 101 is a connector (receptacle) conforming to the USB Type-C standard. The power supply apparatus 200 is connected to the connecting unit 101 via a USB Type-C cable. The connecting unit 101 has a pin assignment as shown in FIG. 5. FIG. 5 is a view for illustrating the pin assignment of the connecting unit 101. The connecting unit 101 has a point-symmetric terminal assignment. The connecting unit 101 includes at least a VBUS terminal, a GND (ground) terminal, a CC (configuration channel) terminal, a D+ terminal, and a D− terminal. The power supply from the power supply apparatus 200 to the power receiving apparatus 100 is performed via the VBUS terminal. A voltage indicating the power capability of the power supply apparatus 200 is applied to the CC terminal. Communication conforming to the USB 2.0 standard is performed via the D+ terminal and the D− terminal. In a case in which the power supply apparatus 200 is an electronic device conforming to a legacy standard, the type of power supply apparatus 200 is determined via the D+ terminal and the D− terminal. The GND (ground) terminal is connected to a ground line.

The power source 102 is a chargeable battery (e.g., a lithium ion battery). The power receiving and supplying unit 103 supplies power received from the power supply apparatus 200 via the VBUS terminal to the power control unit 104 and the power source 102. The power receiving and supplying unit 103 can charge the power source 102 with power received from the power supply apparatus 200 via the VBUS terminal. The power receiving and supplying unit 103 controls the charging of the power source 102. The power receiving and supplying unit 103 can also control power to be received (corresponding to power to be received by the power receiving and supplying unit 103 from the power supply apparatus 200 via the VBUS terminal of the connecting unit 101) so that power to be received will not exceed the power supply capability of the power supply apparatus 200 which has been determined by the power supply capability determination unit 106. In this manner, the power receiving and supplying unit 103 can function as a control unit that controls power to be received from the power supply apparatus 200 via the VBUS terminal. The power control unit 104 can supply power from the power receiving and supplying unit 103 to components of the power receiving apparatus 100.

The resistor 105 is a pull-down resistor for lowering the voltage of the CC terminal of the connecting unit 101 to a predetermined voltage level. The predetermined voltage is a voltage defined by the USB Type-C standard. One end of the resistor 105 is connected to the CC terminal of the connecting unit 101. The other end of the resistor 105 is connected to the GND terminal of the connecting unit 101. The resistor 105 has a predetermined resistance value defined by the USB Type-C standard.

The voltage detection unit 107 is connected to the CC terminal of the connecting unit 101. The voltage detection unit 107 detects a CC voltage (corresponding to a voltage applied to the CC terminal of the connecting unit 101) and notifies the power supply capability determination unit 106 of information indicating the CC voltage. The BC device determination unit 108 is connected to the D+ terminal and the D− terminal. The BC device determination unit 108 determines the type of the power supply apparatus 200 via the D+ terminal and the D− terminal, and notifies the power supply capability determination unit 106 of information related to the determined type. Note that the BC device determination unit 108 determines the type of the power supply apparatus 200 in compliance with the USB BC 1.2 standard.

The power supply capability determination unit 106 determines the power supply capability of the power supply apparatus 200 based on the CC voltage detected by the voltage detection unit 107. FIG. 4 shows the relationship between CC voltage and the power supply capability of the power supply apparatus 200. In a case in which the CC voltage is equal to or higher than 0.25 V but lower than 0.66 V, the power supply capability of the power supply apparatus 200 is Default USB. In a case in which the CC voltage is equal to or higher than 0.66 V but is lower than 1.23 V, the power supply capability of the power supply apparatus 200 is 7.5 W (1.5 A, 5 V). In a case in which the CC voltage is equal to or higher than 1.23 V but equal to or lower than 2.04 V, the power supply capability of the power supply apparatus 200 is 15 W (3 A, 5 V). For example, in a case in which the CC voltage is 0.9 V, the power supply capability determination unit 106 will determine that the power supply capability of the power supply apparatus 200 is 7.5 W (1.5 A, 5 V) because the CC voltage is equal to or higher than 0.66 V but is lower than 1.23 V. The power supply capability determination unit 106 can also acquire information related to the type of power supply apparatus 200 from the BC device determination unit 108, and can determine the power supply capability of the power supply apparatus 200 based on the information related to the type of the power supply apparatus 200. In addition, the power supply capability determination unit 106 can notify the power receiving and supplying unit 103 and the system control unit 109 of the information related to the determined power supply capability of the power supply apparatus 200.

The system control unit 109 includes a memory that stores programs for controlling the components of the power receiving apparatus 100 and a processor for controlling the components of the power receiving apparatus 100 by executing corresponding programs stored in the memory. The processor of the system control unit 109 is, for example, a hardware processor. The system control unit 109 can detect power supplied to each component by the power control unit 104. The system control unit 109 can also calculate the amount of power supplied to each component by the power control unit 104 based on the operation state of the power receiving apparatus 100. The system control unit 109 can also detect the remaining battery amount of the power source 102. The system control unit 109 can control the operation of the power receiving apparatus 100 so that power supplied from the power control unit 104 to each component will be equal to or lower than the power supply capability of the power supply apparatus 200 determined by the power supply capability determination unit 106. For example, in a case in which the power supply apparatus 200 is connected to the connecting unit 101 via a USB Type-C cable, the system control unit 109 can control the power receiving apparatus 100 so that the power receiving apparatus 100 will operate by using power received from the power supply apparatus 200 via the VBUS terminal. In this manner, the system control unit 109 restricts the power consumption of the power receiving apparatus 100 in accordance with the power supply capability of the power supply apparatus 200.

FIGS. 2A and 2B are flowcharts for illustrating an example of the operation of the power receiving apparatus 100 according to the first embodiment.

Step S201 is started when the power supply apparatus 200 is connected to the connecting unit 101 via a USB Type-C cable. In step S201, the power receiving and supplying unit 103 detects the voltage applied to the VBUS terminal of the connecting unit 101. Subsequently, the process of step S202 is started.

In step S202, the power supply capability determination unit 106 determines whether the power supply capability of the power supply apparatus 200 is Default USB. Whether the power supply capability of the power supply apparatus 200 is Default USB is determined based on the CC voltage detected by the voltage detection unit 107. If the CC voltage is equal to or higher than 0.25 V but lower than 0.66 V, the power supply capability determination unit 106 determines that the power supply capability of the power supply apparatus 200 is Default USB. In a case in which the power supply capability of the power supply apparatus 200 is Default USB, it is defined by the USB Type-C standard that the power receiving apparatus 100 will receive power complying with the legacy standard via the VBUS terminal. Hence, if the power supply capability of the power supply apparatus 200 is Default USB (YES in step S202), the process of step S203 is started. If the power supply capability of the power supply apparatus 200 is not Default USB, the power supply capability determination unit 106 will determine the power supply capability of the power supply apparatus 200 based on the CC voltage. After the power supply capability of the power supply apparatus 200 is determined based on the CC voltage (NO in step S202), the process of step S208 is started.

In step S203, the BC device determination unit 108 determines the type of the power supply apparatus 200 via the D+ terminal and the D− terminal. The BC device determination unit 108 supplies, to the power supply capability determination unit 106, the information related to the type of the power supply apparatus 200. The power supply capability determination unit 106 determines the power supply capability of the power supply apparatus 200 based on the information related to the type of the power supply apparatus 200. Subsequently, the process of step S204 is started.

In step S204, the system control unit 109 determines whether the operation power (corresponding to power supplied to each component from the power control unit 104 to operate the power receiving apparatus 100) is higher than the power supply capability of the power supply apparatus 200 determined in step S203. If it is determined that the operation power is higher than the power supply capability of the power supply apparatus 200 (YES in step S204), the process of step S205 is started. If it is determined that the operation power is equal to or lower than the power supply capability of the power supply apparatus 200 (NO in step S204), the process of step S206 is started.

In step S205, the system control unit 109 switches the operation mode or restricts the functions of the power receiving apparatus 100 so that operation power (corresponding to power supplied to each component from the power control unit 104 to operate the power receiving apparatus 100) will be equal to or lower than the power supply capability of the power supply apparatus 200 determined in step S203. Switching from an image capturing mode (an operation mode of obtaining an image by an image capturing unit (not shown)) to a reproduction mode (an operation mode of displaying an image reproduced from a storage medium on a display unit (not shown)) is an example of operation mode switching. Power supplied from the power control unit 104 to each component of the power receiving apparatus 100 in the reproduction mode is lower than power supplied from the power control unit 104 to each component of the power receiving apparatus 100 in the image capturing mode. A state in which some or all of the image capturing functions do not operate is an example of function restriction. Subsequently, the process of step S206 is started.

In step S206, the power receiving and supplying unit 103 determines power to be received (corresponding to power to be received from the power supply apparatus 200 by the power receiving and supplying unit 103 via the VBUS terminal of the connecting unit 101) so that power to be received will not exceed the power supply capability of the power supply apparatus 200 determined in step S203. The power receiving and supplying unit 103 starts the power receiving operation so as to receive, from the power supply apparatus 200, power equal to or lower than the power determined in step S206. Subsequently, the process of step S207 is started.

In step S207, the power receiving and supplying unit 103 starts the charging of the power source 102 together with the supplying of power received from the power supply apparatus 200 via the VBUS terminal of the connecting unit 101 to the power control unit 104 and the power source 102.

As described above, if the power supply capability of the power supply apparatus 200 is not Default USB (NO in step S202), the process of step S208 is started. In step S208, the system control unit 109 determines whether the operation power (corresponding to power supplied from the power control unit 104 to each component to operate the power receiving apparatus 100) is higher than the power supply capability of the power supply apparatus 200 determined in step S202. If it is determined that the operation power is higher than the power supply capability of the power supply apparatus 200 (YES in step S208), the process of step S209 is started. If the operation power is determined to be equal to or lower than the power supply capability of the power supply apparatus 200 (NO in step S208), the process of step S210 is started.

In step S209, the system control unit 109 switches the operation mode or restricts the functions of the power receiving apparatus 100 so that the operation power (corresponding to power supplied from the power control unit 104 to each component to operate the power receiving apparatus 100) will be equal to or lower than the power supply capability of the power supply apparatus 200 determined in step S202. Switching from the image capturing mode to the reproduction mode is an example of operation mode switching. A state in which some or all of the image capturing functions do not operate is an example of function restriction. Subsequently, the process of step S210 is started.

In step S210, the power receiving and supplying unit 103 determines power to be received (corresponding to power to be received from the power supply apparatus 200 by the power receiving and supplying unit 103 via the VBUS terminal of the connecting unit 101) so that power to be received will not exceed the power supply capability of the power supply apparatus 200 determined in step S202. The power receiving and supplying unit 103 starts the power receiving operation so as to receive, from the power supply apparatus 200, power equal to or lower than the power determined in step S210. Subsequently, the process of step S211 is started.

In step S211, the power receiving and supplying unit 103 starts the charging of the power source 102 together with the supplying of power received from the power supply apparatus 200 via the VBUS terminal of the connecting unit 101 to the power control unit 104 and the power source 102. Subsequently, the process of step S212 is started.

In step S212, the BC device determination unit 108 determines the type of the power supply apparatus 200 via the D+ terminal and the D− terminal. The BC device determination unit 108 supplies, to the power supply capability determination unit 106, the information related to the type of the power supply apparatus 200. The power supply capability determination unit 106 determines the power supply capability of the power supply apparatus 200 based on the information related to the type of the power supply apparatus 200. Subsequently the process of step S213 is started.

In step S213, the power supply capability determination unit 106 determines whether the power supply capability of the power supply apparatus 200 has been changed to Default USB. Whether the power supply capability of the power supply apparatus 200 has been changed to Default USB is determined based on the CC voltage detected by the voltage detection unit 107. If the CC voltage is equal to or higher than 0.25 V but is lower than 0.66 V, the power supply capability determination unit 106 will determine that the power supply capability of the power supply apparatus 200 has been changed to Default USB. If the power supply capability of the power supply apparatus 200 has been changed to Default USB (YES in step S213), the process of step S214 is started. If the power supply capability of the power supply apparatus 200 has not been changed to Default USB (NO in step S213), the process of step S213 is repeated.

In step S214, the system control unit 109 determines whether the operation power (corresponding to power supplied to each component from the power control unit 104 to operate the power receiving apparatus 100) is higher than the power supply capability of the power supply apparatus 200 determined in step S212. If it is determined that the operation power is higher than the power supply capability of the power supply apparatus 200 (YES in step S214), the process of step S215 is started. If it is determined that the operation power is equal to or lower than the power supply capability of the power supply apparatus 200 (NO in step S214), the process of step S216 is started.

In step S215, the system control unit 109 switches the operation mode or restricts the functions of the power receiving apparatus 100 so that the operation power (corresponding to power supplied from the power control unit 104 to each component to operate the power receiving apparatus 100) will be equal to or lower than the power supply capability of the power supply apparatus 200 determined in step S212. Switching from the image capturing mode to the reproduction mode is an example of operation mode switching. A state in which some or all of the image capturing functions do not operate is an example of function restriction. Subsequently, the process of step S216 is started.

In step S216, the power receiving and supplying unit 103 determines power to be received (corresponding to power to be received from the power supply apparatus 200 by the power receiving and supplying unit 103 via the VBUS terminal of the connecting unit 101) so that power to be received will not exceed the power supply capability of the power supply apparatus 200 determined in step S212. The power receiving and supplying unit 103 starts the power receiving operation so as to receive, from the power supply apparatus 200, power equal to or lower than the power determined in step S216. Subsequently, the processing of the flowcharts shown in FIGS. 2A and 2B ends.

Note that the transition of the power supply capability of the power supply apparatus 200 to the Default USB is performed in the power supply apparatus 200. Hence, the power supply apparatus 200 may shift the power supply capability of the power supply apparatus 200 to the Default USB before the process of step S212 is started or while the process of step S212 is being performed. If the power supply apparatus 200 shifts the power supply capability of the power supply apparatus 200 to the Default USB before the process of step S212 is started or while the process of step S212 is being performed, the system control unit 109 will interrupt the process of step S212. The system control unit 109 will then complete the shutdown processing within 60 ms from the transition of the power supply capability of the power supply apparatus 200 to the Default USB and will stop receiving power supplied from the power supply apparatus 200 to the VBUS terminal of the connecting unit 101. As a result, even if a state in which the operation of the power receiving apparatus 100 stops unexpectedly occurs, the operation of the power receiving apparatus 100 can be stopped safely.

FIG. 3 is a timing chart for illustrating an example of the operation of the power receiving apparatus 100 according to the first embodiment. FIG. 3 shows a timing chart corresponding to the operation example of the power receiving apparatus 100 from step S212 to step S216.

A transition 301 corresponds to step S213. A transition 302 corresponds to step S216. A period T1 from the transition 301 to the transition 302 is defined to be 60 ms or less in accordance with the USB Type-C standard.

A process 303 corresponds to the process of step S212. A process 304 corresponds to the process of step S215. There is a possibility that a period T2 in which the process 303 is performed may exceed 60 ms if the process is performed in compliance with the USB BC 1.2 standard. For example, if it is set so that the process 303, the process 304, and the transition 302 will be performed after the transition 301, the period T1 may exceed 60 ms and deviate from the USB Type-C standard. Hence, in the first embodiment, it is set so that the process 303 will be started before the transition 301.

Note that if the transition 301 has occurred in the period T2 in which the process 303 is to be performed, the system control unit 109 interrupts the process 303. The system control unit 109 then completes the shutdown processing in 60 ms or less from the transition 301, and stops receiving power supplied from the power supply apparatus 200 via the VBUS terminal of the connecting unit 101. As a result, the operation of the power receiving apparatus 100 can be stopped safely even if a state in which the operation of the power receiving apparatus 100 stops unexpectedly occurs.

As described above, in a case in which the power supply capability of the power supply apparatus 200 is determined in compliance with the USB BC2.1 standard, it may require time that exceeds 60 ms. Hence, the following state may occur if the power supply capability of the power supply apparatus 200 is determined in compliance with the USB BC 1.2 standard after the power supply capability of the power supply apparatus 200 has been determined to be Default USB based on the CC voltage. Power which is to be supplied from the power supply apparatus 200 to the power receiving apparatus 100 via the VBUS terminal of the connecting unit 101 may shift to a voltage conforming to Default USB before the process for determining the power supply capability of the power supply apparatus 200 in compliance with the USB BC 1.2 standard is completed. In this case, power supplied from the power supply apparatus 200 to the power receiving apparatus 100 via the VBUS terminal will fall below the power that the power receiving apparatus 100 will attempt to receive from the power supply apparatus 200 via the VBUS terminal. If power supplied from the power supply apparatus 200 to the power receiving apparatus 100 via the VBUS terminal falls below the power that the power receiving apparatus 100 will attempt to receive from the power supply apparatus 200 via the VBUS terminal, the operation of the power receiving apparatus 100 may stop unexpectedly. In contrast, in the first embodiment, the power supply capability of the power supply apparatus 200 is determined in compliance with the USB BC 1.2 standard before the power which is to be supplied from the power supply apparatus 200 to the power receiving apparatus 100 via the VBUS terminal shifts to power conforming to the Default USB. Hence, according to the first embodiment, it reduces the occurrence of a state in which power to be supplied from the power supply apparatus 200 to the power receiving apparatus 100 via the VBUS terminal will shift to power conforming to the Default USB before the process for determining the power supply capability of the power supply apparatus 200 in compliance with the USB BC 1.2 standard is completed. Therefore, according to the first embodiment, it is possible to reduce the occurrence of a state in which the operation of the power receiving apparatus 100 stops unexpectedly.

Note that the embodiments of the disclosure are not limited to the first embodiment as described above. The embodiments of the disclosure include the first embodiment that has been changed or modified without departing from the scope of the disclosure.

Second Embodiment

Various kinds of functions, processes, or methods described in the first embodiment can be implemented by a personal computer, a microcomputer, a CPU (Central Processing Unit), a processor, or the like by using corresponding programs. In the second embodiment, a personal computer, a microcomputer, a CPU (Central Processing Unit), a processor, or the like will be referred to as a “computer X” hereinafter. Also, in the second embodiment, a program for controlling the computer X, that is, a program for implementing one of the various kinds of functions, processes, or methods described in the first embodiment will be referred to as a “program Y”.

Each of the various kinds of functions, processes, or methods described in the first embodiment is implemented by the computer X executing the program Y. In this case, the program Y is supplied to the computer X via a computer-readable storage medium. The computer-readable storage medium according to the second embodiment includes at least one of a hard disk device, a magnetic storage device, an optical storage device, a magneto-optical storage device, a memory card, a volatile memory, a nonvolatile memory, or the like. The computer-readable storage medium according to the second embodiment is a non-transitory storage medium.

While aspects of the disclosure are described with reference to exemplary embodiments, it is to be understood that the aspects of the disclosure are not limited to the exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications and equivalent structures.

This application claims priority from Japanese Patent Application No. 2017-254850, filed Dec. 28, 2017, which is hereby incorporated by reference herein in its entirety. 

What is claimed is:
 1. An electronic device comprising: a connector that comprises a first terminal for receiving power from a power supply apparatus, a second terminal, a third terminal, and a fourth terminal; a control unit that controls power received from the power supply apparatus via the first terminal; and a determination unit that determines a power supply capability of the power supply apparatus by using the second terminal or the third terminal and the fourth terminal, wherein the determination unit determines the power supply capability of the power supply apparatus by using the third terminal and the fourth terminal before a predetermined transition occurs in the second terminal.
 2. The electronic device according to claim 1, wherein the determination unit determines the power supply capability of the power supply apparatus based on a voltage of the second terminal.
 3. The electronic device according to claim 1, wherein a voltage of the second terminal before the occurrence of the predetermined transition is a voltage defined in USB Type-C standard.
 4. The electronic device according to claim 1, wherein the determination unit determines the power supply capability of the power supply apparatus based on a type of the power supply apparatus which is determined via the third terminal and the fourth terminal.
 5. The electronic device according to claim 1, wherein before the occurrence of the predetermined transition, the control unit controls power to be received from the power supply apparatus in accordance with the power supply capability of the power supply apparatus determined by using the second terminal.
 6. The electronic device according to claim 1, wherein after the occurrence of the predetermined transition, the control unit controls power to be received from the power supply apparatus in accordance with the power supply capability of the power supply apparatus determined by using the third terminal and the fourth terminal.
 7. The electronic device according to claim 1, wherein in a case in which the predetermined transition occurs in the second terminal before the power supply capability of the power supply apparatus is determined by using the third terminal and the fourth terminal, the control unit stops receiving power from the power supply apparatus.
 8. A method comprising: starting to receive power from a power supply apparatus via a first terminal for receiving power from the power supply apparatus; determining a power supply capability of the power supply apparatus by using a second terminal; and determining, before a predetermined transition occurs in the second terminal, the power supply capability of the power supply apparatus by using a third terminal and a fourth terminal.
 9. A non-transitory storage medium that stores a program causing a computer to execute a method, the method comprising: starting to receive power from a power supply apparatus via a first terminal for receiving power from the power supply apparatus; determining a power supply capability of the power supply apparatus by using a second terminal; and determining, before a predetermined transition occurs in the second terminal, the power supply capability of the power supply apparatus by using a third terminal and a fourth terminal. 